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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at */
#ifndef mozilla_dom_WheelEvent_h_
#define mozilla_dom_WheelEvent_h_
#include "mozilla/dom/MouseEvent.h"
#include "mozilla/dom/WheelEventBinding.h"
#include "mozilla/EventForwards.h"
namespace mozilla::dom {
class WheelEvent : public MouseEvent {
WheelEvent(EventTarget* aOwner, nsPresContext* aPresContext,
WidgetWheelEvent* aWheelEvent);
static already_AddRefed<WheelEvent> Constructor(const GlobalObject& aGlobal,
const nsAString& aType,
const WheelEventInit& aParam);
virtual JSObject* WrapObjectInternal(
JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override {
return WheelEvent_Binding::Wrap(aCx, this, aGivenProto);
double DevToCssPixels(double aDevPxValue) const {
if (!mAppUnitsPerDevPixel) {
return aDevPxValue;
return aDevPxValue * mAppUnitsPerDevPixel / AppUnitsPerCSSPixel();
// NOTE: DeltaX(), DeltaY() and DeltaZ() return CSS pixels when deltaMode is
// DOM_DELTA_PIXEL. (The internal event's delta values are device pixels
// if it's dispatched by widget)
double DeltaX(CallerType);
double DeltaY(CallerType);
double DeltaZ(CallerType);
uint32_t DeltaMode(CallerType);
int32_t WheelDelta(CallerType aCallerType) {
int32_t y = WheelDeltaY(aCallerType);
return y ? y : WheelDeltaX(aCallerType);
static constexpr int32_t kNativeTicksToWheelDelta = 120;
static constexpr double kTrustedDeltaToWheelDelta = 3.0;
int32_t WheelDeltaX(CallerType);
int32_t WheelDeltaY(CallerType);
void InitWheelEvent(const nsAString& aType, bool aCanBubble, bool aCancelable,
nsGlobalWindowInner* aView, int32_t aDetail,
int32_t aScreenX, int32_t aScreenY, int32_t aClientX,
int32_t aClientY, uint16_t aButton,
EventTarget* aRelatedTarget,
const nsAString& aModifiersList, double aDeltaX,
double aDeltaY, double aDeltaZ, uint32_t aDeltaMode);
~WheelEvent() = default;
double ToWebExposedDelta(WidgetWheelEvent&, double aDelta,
nscoord aLineOrPageAmount, CallerType);
int32_t mAppUnitsPerDevPixel;
} // namespace mozilla::dom
already_AddRefed<mozilla::dom::WheelEvent> NS_NewDOMWheelEvent(
mozilla::dom::EventTarget* aOwner, nsPresContext* aPresContext,
mozilla::WidgetWheelEvent* aEvent);
#endif // mozilla_dom_WheelEvent_h_